Image-coding apparatus and image-coding method, data-coding apparatus and data-coding method, data-recording apparatus and data-recording medium

ABSTRACT

The image-coding apparatus is provided with: a motion-prediction-compensation circuit  36,  which performs motion-prediction-compensation independently for each frame image in a composite-frame image that is obtained by forming abotuidary between and by connecting the respective frame images that make up a plurality of different moving images; a quantization circuit  32,  which performs quantization for each frame image based on the results of motion prediction compensation for each frame image; a variable-length coding circuit  25,  which codes each respective moving image by coding each of the frame images based on the quantization results for each frame image; and a control circuit  22,  which performs control such that motion prediction compensation, quantization and coding are repeated for a plurality of successive composite-frame images.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image-coding apparatus andimage-coding method, data-coding apparatus and data-coding method,data-recording apparatus and data-recording medium, and in particular,the present invention relates to an image-coding apparatus andimage-coding method for coding moving images, a data-coding apparatusand data coding method for coding input data that contains moving imagesand corresponding sound data, and a data-recording apparatus thatincludes the data-coding apparatus and data-recording medium on which animage-coding program or data-coding program is recorded.

2. Description of the Related Art

Conventionally, the contents of a program obtained from a broadcastsignal are recorded on a recording medium such as videotape.

However, up until now, two programs that were broadcast during the sametime period were not recorded simultaneously.

Moreover, when using conventional recording equipment for recording twodifferent programs at the same time, it was necessary to use two systemsfor coding the moving images. This led to the problem of the need forhigh-cost recording equipment with complicated construction, as well asthe need for employing a special recording method, which in turnedrequired that a special reproduction method be used for reproduction.

SUMMARY OF THE INVENTION

In view of the problems described above, it is the object of the presentinvention to provide an image-coding apparatus and image-coding method,a data-coding apparatus and data-coding method, and a data-recordingapparatus and data-recording medium, which contains a recordedimage-coding program or data-coding program, that will make it possibleto simply record two or more programs simultaneously, as well as use aconventional reproduction method for reproducing the recorded programs.

The above object of the present invention can be achieved by an imagecoding apparatus of the present invention, which codes moving images bycoding a composite frame image that is obtained by fanning a boundarybetween and by connecting the respective frame images of a plurality ofdifferent moving images. The image coding apparatus is provided with: amotion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; and a control device for controlling saidmotion-prediction-compensation device, quantization device and codingdevice such that said motion prediction compensation, quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively.

According to the present invention, frame images, having a plurality ofmoving images, are collected together as a composite frame image, andthe coding process is executed for each individual frame, and thus it ispossible to code a plurality of moving images simultaneously with asingle coding apparatus. In addition, since each frame image in onecomposite frame image is coded individually, it is possible to decodethe coded moving image using a conventional decoding method.

In one aspect of the present invention, themotion-prediction-compensation device executes said motion predictioncompensation by setting a search area for said motion predictioncompensation within only the range of said frame images contained insaid composite frame image, and detecting the motion vector.

According to this aspect in the motion-prediction-compensation process,movement vectors are detected by setting a search area that is withinonly the range of frame images of the composite frame image, so it ispossible to code a plurality of moving images at the same time using thesame coding method as used for a non-composite moving image.

In another aspect of the present invention, the quantization deviceindependently performs said quantization for each of said frame image insaid composite frame image.

According to this aspect, the quantization process is performedindependently for each frame image, so it is possible to performquantization accurately for each frame image.

In further aspect of the present invention, the image-coding apparatusis further provided with a discrete cosine transform device forperforming discrete cosine transform of each said frame image based onthe results of said motion prediction compensation that is performed oneach said frame image, wherein said quantization device performs saidquantization for each of said frame image of which discrete cosinetransform is performed.

According to this aspect, discrete-cosine-transform processing isperformed for each frame image, so it is possible to code each movingimage with a high coding rate.

In further aspect of the present invention, the motion predictioncompensation, quantization process and coding process are executedaccording to Moving Picture Experts Group (MPEG) format.

According to this aspect, it is possible to compress and code aplurality of moving images simultaneously.

The above object of the present invention can be achieved by adata-coding apparatus of the present invention, which includes animage-coding apparatus for coding moving images by coding a compositeframe image that is obtained by forming a boundary between and byconnecting the respective frame images of a plurality of differentmoving images. The image-coding apparatus is provided with: amotion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; and a control device for controlling saidmotion-prediction-compensation device, quantization device and codingdevice such that said motion prediction compensation, quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively. The data-coding apparatus isprovided with: a separation device for separating moving images andsound data from a plurality of input data that contain said movingimages and said sound data that correspond to said moving images; afirst composite-image device for reducing the amount of data in saidframe images of said separated moving images, and for generating saidcomposite frame image to output that image to said image-codingapparatus; a sound-coding device for coding said separated sound datasimultaneously with coding of the corresponding said moving images andfor generating coded sound data; and a second composite-image device forcombining corresponding said coded moving images and said coded sounddata and for generating a plurality of said coded input data.

According to the present invention, the sound data is coded in parallelwith coding of the moving images, after which, they are combined, and soit is possible to code a plurality of input data simultaneously.Therefore, it is possible to code a plurality of moving imagessimultaneously with simple construction, and when decoding the codedmoving images it is possible to use a conventional decoding method asis.

The above object of the present invention can be achieved by adata-recording apparatus of the present invention, which includes animage-coding apparatus for coding moving images by coding a compositeframe image that is obtained by forming a boundary between and byconnecting the respective frame images of a plurality of differentmoving images. The data-recording apparatus is provided with: amotion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; a control device for controlling saidmotion-prediction-compensation devices quantization device and codingdevice such that said motion prediction compensation, quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively; a separation device forseparating moving images and sound data from a plurality of input datathat contain said moving images and said sound data that correspond tosaid moving images; a first composite-image device for reducing theamount of data in said frame images of said separated moving images, andfor generating said composite frame image to output that image to saidimage-coding apparatus; a sound-coding device for coding said separatedsound data simultaneously with coding of the corresponding said movingimages and for generating coded sound data; a second composite-imagedevice for combining corresponding said coded moving images and saidcoded sound data and for generating a plurality of said coded inputdata; and a recording device for separately recording said coded inputdata on a recording medium.

According to the present invention, it is possible to code and record aplurality of input data simultaneously. Therefore, it is possible tocode and record input data from a plurality of sources simultaneouslywith simple construction, and when decoding and reproducing the recordedinput data, it is possible to use conventional decoding and reproductionmethods as are.

The above object of the present invention can be achieved by animage-coding method of the present invention for coding said movingimages by coding a composite frame image that is obtained by forming aboundary between and by connecting the respective frame images of aplurality of different moving images. The image-coding method isprovided with the processes of: independently performing motionprediction compensation for said frame images in said composite frameimage; performing quantization for each of said frame images based onthe results of said motion-prediction-compensation that is performed foreach of said frame images; coding said moving images by coding each ofsaid frame images based on the results of said quantization that isperformed for each of said frame images; and repeating said motionprediction compensation, quantization and coding for a plurality ofcontinuous said composite frame images.

According to the present invention, the frame images, which comprise aplurality of moving images, are combined into a composite frame image,and coding is performed for each image individually, so it is possibleto code a plurality of moving images simultaneously with one codingapparatus. Moreover, since the frame images within a single compositeframe image are coded individually, it is possible to decode the codedmoving images using a conventional decoding method as is.

In one aspect of the present invention, the process of independentlyperforming motion prediction compensation executes saidmotion-prediction-compensation by setting a search area for saidmotion-prediction-compensation within only the range of said frameimages that are included in one said composite frame image and detectingthe motion vectors.

According to this aspect, in the movement-prediction-compensationprocess, movement vectors are detected by setting a search area that iswithin only the range of frame images of the composite frame image, soit is possible to code a plurality of moving images at the same timeusing the same coding method as used for a non-composite moving image.

In another aspect of the present invention, the process of performingquantization independently performs quantization for each of said frameimages in said composite frame image.

According to this aspect, the quantization process is performedindependently for each frame image, so it is possible to performquantization accurately for each frame image.

In further aspect of the present invention, the image-coding method isfurther provided with: the process of performing discrete cosinetransform for each of said frame images based on the results of saidmovement-prediction-compensation that is performed for each of saidframe images, and wherein said process for performing quantizationexecutes quantization for each of said frame images after discretecosine transformation.

According to this aspect, discrete-cosine-transform processing isperformed for each frame image, so it is possible to code each movingimage with a high coding rate.

In further aspect of the present invention, the motion predictioncompensation, quantization and coding are executed based on MPEG format.

According to this aspect, it is possible to compress and code aplurality of moving images simultaneously.

The above object of the present invention can be achieved by adata-coding method of the present invention that includes theimage-coding method for coding said moving images by coding a compositeframe image that is obtained by forming a boundary between and byconnecting the respective frame images of a plurality of differentmoving images. The image-coding method is provided wit the processes of:independently performing motion prediction compensation for said frameimages in said composite frame image; performing quantization for eachof said frame images based on the results of saidmotion-prediction-compensation that is performed for each of said frameimages; and coding said moving images by coding each of said frameimages based on the results of said quantization that is performed foreach of said frame images; and repeating said motion predictioncompensation, quantization and coding for a plurality of continuous saidcomposite frame images. The data-coding method is provided with theprocesses of: separating moving images and sound data from a pluralityof input data that includes said moving images and corresponding sounddata; generating said composite-frame image to execute said image-codingmethod after reducing the amount of data in said frame images containingsaid separated moving images; coding each of separated said sound datasimultaneously with coding of corresponding said moving images togenerate coded sound data; and combining corresponding said coded movingimages and said coded sound data to generate a plurality of said codedinput data.

According to the present invention, the sound data is coded in parallelwith coding of the moving images, after which, they are combined, and soit is possible to code a plurality of input data simultaneously.Therefore, it is possible to code input data from a plurality of sourcessimultaneously with simple construction, and when decoding the codedinput data, it is possible to use a conventional decoding method as is.

The above object of the present invention can be achieved by adata-recording medium of the present invention on which an image-codingprogram is recorded so that it is readable by a computer, which isincluded in an image-coding apparatus that codes said moving images bycoding a composite-frame image that is obtained by forming a boundarybetween and by connecting the respective frame images of a plurality ofdifferent moving images. The image-coding program causes the computer tofunction as: a motion-prediction-compensation device for independentlyperforming a motion prediction compensation for each of said frameimages in said composite frame image; a quantization device forperforming quantization for each of said frame images based on theresults of said motion prediction compensation that was performed foreach said frame image; a coding device for coding said moving images bycoding each said frame image based on the results of said quantizationthat was performed for each said frame image; and a control device forcontrolling said motion-prediction-compensation device, quantizationdevice and coding device such that said motion prediction compensation,quantization and coding are performed for a plurality of continuouscomposite-frame images by said motion-prediction-compensation device,quantization device and coding device, respectively.

According to the present invention, the computer functions to combine aplurality of moving images of a frame image into a composite frame imageand executes the coding process for each individually, so it is possibleto code a plurality of moving images simultaneously with one codingapparatus. Moreover, the computer functions to code the frame images inone composite frame image individually, so it is possible to decode thecoded moving images using a conventional decoding method as is.

In one aspect of the present invention, themotion-prediction-compensation device performs said motion predictioncompensation by setting the search area for themotion-prediction-compensation within only the range of said frameimages that are included in one said composite-frame image and detectingthe motion vectors.

According to this aspect, the computer functions to detect movementvectors in the movement-prediction-compensation process by setting asearch area that is within only the range of frame images of thecomposite frame image, so it is possible to code a plurality of movingimages at the same time using the same coding method as used for anon-composite moving image.

In another aspect of the present invention, the quantization deviceperforms quantization independently for each of said frame images insaid composite-frame image.

According to this aspect, the computer performs quantizationindependently for each frame image, so it is possible to quantize eachframe image accurately.

In further aspect of the present invention, the image-coding programfurther causes the computer to function as: a discrete cosine transformdevice for performing discrete cosine transformation of each of saidframe images based on the results of said motion-prediction-compensationthat is performed for each of said frame images, wherein saidquantization device performs quantization for each of said frame imagesafter discrete cosine transformation.

According to this aspect, the computer performs discrete cosinetransform for each frame image, so it is possible to code each movingimage with a high coding rate.

In further aspect of the present invention, themotion-prediction-compensation, quantization and coding are executedbased on MPEG format.

According to this aspect, it is possible to compress and code aplurality of moving images simultaneously.

The above object of the present invention can be achieved by adata-recording medium of the present invention on which a coding programis recorded so that it is readable by a computer, which is included in adata-coding apparatus that includes an image-coding apparatus that codessaid moving images by coding a composite-frame image that is obtained byforming a boundary between and by connecting the respective frame imagesof a plurality of different moving images. The coding program thatincludes an image-coding program causing the computer to function assaid image-coding apparatus. The image-coding apparatus is providedwith: a motion-prediction-compensation device for independentlyperforming a motion prediction compensation for each of said frameimages in said composite frame image; a quantization device forperforming quantization for each of said frame images based on theresults of said motion prediction compensation that was performed foreach said frame image; a coding device for coding said moving images bycoding each said frame image based on the results of said quantizationthat was performed for each said frame image; and a control device forcontrolling said motion-prediction-compensation device, quantizationdevice and coding device such that said motion prediction compensation,quantization and coding are performed for a plurality of continuouscomposite-frame images by said motion-prediction-compensation device,quantization device and coding device, respectively. In addition, thecoding program further causes the computer to function as: a separationdevice for separating moving images and sound data from a plurality ofinput data that includes said moving images and corresponding sounddata; a first composite-image device for reducing the amount of data insaid frame images containing said separated moving images, and forgenerating said composite-frame image to output that image to saidcomputer functioning as said image-coding apparatus; a sound-codingdevice for coding each of separated said sound data simultaneously withcoding of corresponding said moving images, and for generating codedsound data; and a second composite-image device for combiningcorresponding said coded moving images and said coded sound data, andfor generating a plurality of said coded input data.

According to the present invention, the computer codes sound data inparallel with the coding of moving images, and then combines them, so itis possible to code a plurality of input data simultaneously. Therefore,it is possible to code input data from a plurality of sourcessimultaneously with simple construction, and when decoding the codedinput data, it is possible to use a conventional decoding method as is.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the basic construction of anembodiment of a data recording apparatus;

FIG. 2 is a block diagram showing the basic construction of an imagecoding apparatus;

FIG. 3 is a diagram showing the operation of a raster/macro-blockconversion circuit;

FIG. 4A is a diagram showing a first example (I) of the operation of themovement-prediction-compensation circuit for when the search area andboundary line are separated;

FIG. 4B is a diagram showing a first example (I) of the operation of themovement-prediction-compensation circuit for when the search area andboundary line overlap;

FIGS. 5A and 5B are diagrams showing a second example (II) of theoperation of the movement-prediction-compensation circuit;

FIG. 6 is a diagram showing the construction of a header-generationmemory;

FIG. 7 is a diagram showing the data structure after a header has beenadded; and

FIG. 8 is a block diagram showing the basic construction of amultiplexing circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be describedwith reference to the drawings.

The embodiment described below, to which the present invention isapplied, is a data recording apparatus that is capable of coding inputdata for both images and sound from two sources simultaneously, andrecording that data on a recording medium such as a writable opticaldisc or hard disc, and codes the input data from a source and records iton a recording medium using a conventional method.

Here the two sources of input data, for example, are two broadcastprograms that are broadcast during the same time period and are to berecorded at the same time.

First, FIG. 1 will be used to explain the basic construction andoperation of the data recording apparatus of this embodiment. FIG. 1 isa block diagram showing the basic construction of the data recordingapparatus.

As shown in FIG. 1, the data recording apparatus R of this embodimentcomprises: switches 1, 3 and 9, a separating circuit 2 as a separationdevice, down sampling units 4 and 5, sound coding circuits 6 and 7 assound-coding device, a composite-image-formation circuit 8 as a firstway of forming composite image data, a coding device 10, a multiplexingcircuit 11 as a second composite-image device, a CPU 12 and a recordingunit 13 as a recording device.

Next, the operation will be explained.

First, the operation of using the data recording apparatus R of thisembodiment to code data information from only one source and record iton a recording medium 14 will be explained.

First, when coding and recording input data from only one source, theswitch 1 is turned OFF according to a control signal Scw1 from the CPU12, and switches 3 and 9 are switched to the up position in FIG. 1according to respective control signals Scw2 or Scw3 from the CPU. Whenthis happens, the CPU 12 is instructed by a control unit (not shown inthe figure) to code and record data from only one source, and outputscontrol signals Scw1 to Scw3 for the appropriate operation.

In this case, the down sampling units 4 and 5, composite-image-formationcircuit 8 and sound coding circuit 7 do not operate.

The aforementioned input data from one source that is to be recorded onthe recording medium 14 is input to the separating circuit 2 as inputdata Sina.

Next, the separating circuit 2 separates the input data Sina into imagedata Sva, which contains only images, and sound data Saa, which containsonly speech and other sound (simply called sound below), based on acontrol signal from the CPU 12, and outputs the separated data to switch3 and the sound coding circuit 6, respectively.

Here, the switches 3 and 9, which are switched to the up position inFIG. 1, output the image data Sva as is to the image coding circuit 10as switch signals Sv1 and Sv2.

Also, the image coding circuit 10 compresses and codes the image dataSva of the switch signal Sv2 according to a control signal Sce from theCPU using the well known MPEG format, to create coded image data Sed andoutputs it to the multiplexing circuit 11.

On the other hand, the sound coding circuit 6 codes the input sound dataSaa using the well know MPEG format, to create coded sound data Seaa andoutputs it to the multiplexing circuit 11.

Then according to a control signal Scm from the CPU 12, the multiplexingcircuit 11 performs multiplexing for each image and sound thatcorresponds to the coded image data Sed and coded sound data Seaa tocreate multiplexed data Smx, and outputs that data to the recording unit13.

The recording unit 13 then performs the preset recording process for themultiplex data Smx and creates recording data Sr and records thatrecording data Sr on the recording medium 14.

When the recording process performed by the recording unit 13 is for arecording medium 14 that is a writable optical disc, first the recordingunit 13 performs a waveform shaping process for the multiplexed data Smxand generates a strength varying optical beam that corresponds to thechanges in the multiplexed data Smx, then records that multiplexed dataSmx on the recording medium 14.

On the other hand, when the recoding medium 14 is a hard disc, therecording unit 13 records the created recording data Sr directly as ison the recording medium 14.

Next, FIG. 1 will be used to explain the operation of this embodiment ofthe invention when recording input data from two sources simultaneously.

First, in the case of coding and recording input data from two sources,the switch 1 is turned ON according to a control signal Scw1 from theCPU 12, and the switches 3 and 9 are switched to the down position inFIG. 1 by control signals Scw2 and Scw3 from the CPU 12, respectively.The CPU 12 is instructed by a control unit (not shown in the figure) tocode and record input data from two sources, and outputs control signalsScw1 to Scw3 for the appropriate operation, similar to the casedescribed above.

First, the input data from one of the two sources to be recorded on therecording medium 14, is input to the separating circuit 2 as input dataSina, and the input data from the other source is input to theseparating circuit 2 as input data Sinb by way of the switch 1.

Then, based on a control signal Scs from the CPU 12, the separatingcircuit 2 synchronizes frames between the input data Sina and input dataSinb. That is, it matches the input timing for the down-sampling unit 4for one frame image of the image data Sva (to be described later) withthe input timing for the down-sampling unit 5 for one frame image of theimage data Svb (to be described later). Then separates the input dataSina into image data Sva, which contains only images, and sound dataSaa, which contains only sound, and outputs them to the down-samplingunit 4 (by way of switch 3) and the sound-coding circuit 6,respectively, and also separates the input data Sinb into image dataSvb, which contains only images, and sound data Sab, which contains onlysound, and outputs them to the down-sampling unit 5 and sound-codingcircuit 7, respectively.

Then, the down-sampling unit 4 thins out only the amount of data for thehorizontal direction of the frame images contained in the image data Svato half the amount and creates thinned-out image data Sda, and thenoutputs the data to the composite-image-formation circuit 8.

At the same time, the down-sampling circuit 5 thins out only the amountof data for the horizontal direction of the frame images contained inthe image data Svb to half the amount and creates thinned-out image dataSdb, and then outputs the data to the composite-image-formation circuit8.

In this way, synchronization is obtained between frames of thethinned-out image data Sda and thinned-out image data Sdb.

Then, according to a control signal Scc from the CPU 12, thecomposite-image-formation circuit 8 connects one frame image from thethinned-out image data Sda and a corresponding frame image from thethinned-out image data Sdb side-by-side in the horizontal direction, tocreate composite image data Scv that comprises a composite frame imagehaving the same amount of data as one frame image of the original imagedata Sva or image data Svb, and then outputs the data as a switch signalSv2 to the image-coding circuit 10 via the switch 9, which is switchedto the down position in FIG. 1.

Here, based on a control signal Sce from the CPU 12, the image-codingcircuit 10 compresses and codes the composite image data Scv as switchsignal Sv2, in compliance with the MPEG format, described later, tocreate coded image data Sed, then outputs the data to the multiplexingcircuit 11. Then, also the image-coding circuit 10 creates a timingsignal St in order to match the timing at which the portion of thecomposite image data Scv that corresponds to the image data Sva isoutput from the image-coding circuit 10 as coded image data Sed, or thetiming at which the portion of the composite image data Scv thatcorresponds to the image data Svb is output from the image-codingcircuit 10 as coded image data Sed, with the timing at which the codedsound data Seaa or coded sound data Seab, to be described later, isoutput to the multiplexing circuit 11, and similarly outputs the data tothe multiplexing circuit 11.

On the other hand, the sound-coding circuit 6 codes the input sound dataSaa using MPEG format or the like to create coded sound data Seaa, andoutputs the data to the multiplexing circuit 11.

Furthermore, the sound-coding circuit 7 codes the input sound data Sabusing MPEG format or the like to create coded sound data Seab, andoutputs the data to the multiplexing circuit 11.

Then, according to a control signal Scm from the CPU 12 and theaforementioned timing signal St, the multiplexing circuit 11 performsmultiplexing for the each image and sound corresponding to the imagedata Sva contained in the coded image data Sed, and corresponding codedsound data Seaa, to create multiplexed data Smx, and then outputs thedata to the recording unit 13. In addition, the multiplexing circuit 11performs multiplexing for each image and sound corresponding to theimage data Svb contained in the coded image data Sed, and correspondingcoded sound data Seab, to create multiplexed data Smx, and then outputsthe data to the recording unit 13.

The recording unit 13, then performs a preset recording process for themultiplexed data Smx to create recording data Sr, and then records therecording data Sr on a recording medium 14.

Next, FIG. 2 thru FIG. 7 will be used to explain the construction andoperation of the image-coding circuit 10 when coding input data Sina andSinb.

FIG. 2 is a block diagram showing the construction of the image-codingcircuit 10, FIG. 3 is a diagram showing the operation of araster/macro-block conversion circuit, FIG. 4 and FIG. 5 show theoperation of a movement-prediction-compensation circuit, and FIG. 6 andFIG. 7 show the operation of a header-generation circuit.

As shown in FIG. 2, the image-coding circuit 10 comprises animage-arrangement circuit 20, a raster/macro-block conversion circuit21, a control circuit 22 as a control device, a table memory 23, acoding circuit 24, a variable-length coding circuit 25 as a codingdevice, a header-generation circuit 26, switches 27 and 27, and a bufferunit 28 having output buffers 28 a, 28 b.

Moreover, the coding circuit 24 comprises a subtracter 30, a discretecosine transform (DCT) circuit 31, a quantization circuit 32 as aquantization device, a inverse-quantization circuit 33, a inverse DCTcircuit 34, a frame memory 35, a movement-prediction-compensationcircuit 36 as a motion-prediction-compensation device, and an adder 37.

Next, the operation will be explained.

First, the image-arrangement circuit 20 rearranges in frame units (or inthe lower-order picture units), the order of each of the frame imagescontained in the composite image data Scv, or switch signal Sv2, intothe order executed by the coding process to be described later, tocreate a rearranged image signal Scg that includes the rearranged frameimages, and then outputs the signal to the raster/macro-block conversioncircuit 21.

In the arrangement process, the frame images, which will be theso-called I pictures (Intra-Pictures) in the MPEG format, and the frameimages, which will be the so-called P pictures (Predictive-Pictures),are moved and rearranged so they are before the frame images, which willbe the so-called B pictures (Bi-directionally Predictive-Pictures).

At the same time as this, the image-arrangement circuit 20 creates aframe-synchronization signal Sfs that shows the output timing from theimage-arrangement circuit 20 of each of the rearranged frame images, andoutputs the signal to the raster/macro-block conversion circuit 21.

Next, according to the frame-synchronization signal Sfs, theraster/macro-block conversion circuit 21 temporarily stores thepicture-element data (brightness data, color data, etc.) for each frameinput in the horizontal scanning order (raster order) as therearranged-image data Scg, as shown in FIG. 3, and then createsmacro-blocks MB, as shown in FIG. 3, from the picture-element data, andoutputs macro-block signals Smb to the coding circuit 24 in the order ofthe created macro-blocks MB.

Then, as shown in FIG. 3, the frame images GV that are input asrearranged-image signals Scg are input in horizontal scanning order withthe images GVA that correspond to the image data Sva and the images GVBthat correspond to the image data Svb connected on the left and right inthe horizontal direction along a boundary L. The raster/macro-blockconversion circuit 21 uses the picture-element data for adjoining 16picture elements ×16 picture elements to form a single macro-block MB.Moreover, of the frame image GVM contained in the macro-block signalSmb, the 22 horizontal ×30 vertical macro blocks MB on the left side ofthe boundary L become the image GVMA that corresponds to the image dataSva, and the 22 horizontal ×30 vertical macro blocks MB on the rightside become the image GVMB that corresponds to the image data Svb. Inother words, a single frame image GVM contains 1320 macro blocks MB.

Here, as shown by the section with diagonal lines at the bottom of FIG.3, a slice SL, or basic unit in the MPEG format, comprises 22 macroblocks in the horizontal direction of either the image GVMA or GVMB.

At the same time as this, the raster/macro-block conversion circuit 21creates number data Sma that gives a number for each macro block MB thatwas created (refer to FIG. 3), and outputs the data to the controlcircuit 22.

Next, the macro-block signals Smb that are input to the coding circuit24 are output to the subtracter 30 and motion-prediction-compensationcircuit 36.

When the macro-block signals Smb are output to the subtracter 30, acompensation signal Se output from the motion-prediction-compensationcircuit 36, to be described later, is subtracted from the macro-blocksignals Smb, arid output to the DCT circuit 31 as a subtraction signalSa.

Next, the DCT circuit 31 performs DCT to compress the subtraction signalSa, or in other words, transforms the spatial coordinate component ofeach of the macro blocks MB shown at the bottom of FIG. 3 to a frequencycomponent, and performs this transformation process in the order thatthe macro blocks MB input as macro-block signals Smb were input tocreate a transform signal Sdc that contains the macro blocks that weretransformed to a frequency component, and then outputs the signal to thequantization circuit 32.

Here, the quantization circuit 32 performs quantization of the transformsignal Sdc at a processing rate that corresponds to thequantization-scale code that is given by the rate signal Srr, to bedescribed later, that is sent from the control circuit 22, and creates aquantized signal Sq and outputs the signal to the variable-length codingcircuit 25 and inverse-quantization circuit 33.

The quantization process that is performed by the quantization circuit33 truncates the bits of the picture-element data included in each macroblock MB, and compresses the amount of data.

The processing rate is set by the control circuit 22 to prevent anoverflow in the output buffers 28 a and 28 b in the buffer unit 28, andto prevent overflow or underflow in the reproduction buffer that is usedwhen reproducing the data that are recorded on the recording medium 14.

Furthermore, in this embodiment, in the step of outputting data to thebuffer unit 28, the image data that corresponds to image data Sva (imagedata DA described below) and the image data that corresponds to theimage data Svb (image data DB described below) are output separately so,quantization by the quantization circuit 32 is executed separately andindependently for the image data that corresponds to the image data Svaand the image data that corresponds to the image data Svb in thetransform signal Sdc.

Therefore, according to a storage-amount signal Sdd, described later,output from the buffer unit 28, the control circuit 22 references thenumber of the macro block that is currently being quantized (input fromthe raster/macro block conversion circuit 21 as number data Sma), andfrom this number determines whether there is macro block MB thatcontains image data corresponding to the image data Sva, or whetherthere is macro block MB that contains image data corresponding to theimage data Svb, and executes control for respective processing ratesimultaneously and independently while changing the object for thecontrol (with the slice SL as the basic unit).

Next, the inverse-quantization circuit 33 performs inverse quantizationfor the quantized signal Sq to create an inverse-quantized signal Siq,and outputs the signal to the inverse DCT circuit 34.

The inverse DCT circuit 34 performs inverse DCT (inverse discrete cosinetransform) for the inverse-quantized signal Siq, and outputs the resultto the adder 37 as an inverse-transform signal Sid.

Through the operation of the inverse-quantization circuit 33 and inverseDCR circuit 34, the reproduction process for creating the previous frameimage that is used in the motion-prediction-compensation process isperformed for the quantization signal Sq that is described later.

Next, the reproduced inverse-transform signal Sid and the compensationsignal Se, described later, are added together by the adder 37 to createthe previous frame image, and this previous frame image is saved as theprevious frame signal Sad in the frame memory 35 for the timecorresponding to the input period of one frame image, and then it isoutput to the motion-prediction-compensation circuit 36.

Then, based on a control signal Sine from the control circuit 22, themotion-prediction-compensation circuit 36 detects the motion vectors inthe MPEG format for each of the macro blocks MB in the macro-blocksignal Smb and both image data Sva or Svb. Also, themotion-prediction-compensation circuit 36 uses the motion vectors toperform the motion-prediction-compensation process, and creates acompensation signal Se that contains corrected frame images, and outputsthe signal to the subtracter 30 and adder 37.

In this embodiment, detection of the motion vectors is performedindependently for the frame images that correspond to the image data Svaand the frame images that correspond to the image data Svb.

The search area used in detection of the motion vectors is set such thatit does not cross the boundary line between the images that correspondto the image data Sva and the image data Svb in one previous frameimage. The search area is the detection range when detecting the macroblock in the previous frame image that corresponds to the macro block tobe predicted in the current frame image that is input as the macro blocksignal Smb. The macro block to be predicted in the current frame imageis a macro block MB that is the object of motion-vector detection. Themacro block in the previous frame image corresponding to the macro blockMB contains the image structure of the macro block MB. The search areais normally the area comprising a previously set specified number ofmacro blocks MB where one macro block MB in a single frame image is thecenter.

In more detail, as shown in FIG. 4a, when the boundary line L betweenthe image GRA and the image GRB in one previous frame image GR and thesearch area SA at that time are separated, the width of the search areaSA is set as the area which includes the specified number of macroblocks MB where a macro block MBR is in the center. The macro block MBRis in a position in the previous frame image GR that is identical to theposition of the macro block MBN to be predicted in the current frameimage GN. Th image GRA corresponds to the image data Sva, and the imageGRB corresponds to the image data Svb. Naturally, when the macro blockMBN to be predicted is in the area of image GNA, the macro block MBR isin the area of image GNA, and when the macro block MBN to be predictedis in the area of image GNB, the macro block MBR is in the area of imageGNB.

However, on the other hand, when the aforementioned boundary line L andsearch area SA′ overlap, as shown in FIG. 4b, the width of the searcharea SA′ is narrower than the area which includes the specified numberof macro blocks MB in which the macro block MBR is the center, and thatsearch area SA′ is limited to the area that comes in contact with theboundary line L but does not cross over the boundary line L.

Next, FIG. 5a and FIG. 5b will be used to explain the method for settingthe search area SA or SA′ that is used by themotion-prediction-compensation circuit 36.

As shown in FIG. 5a, a table T is stored beforehand in the table memory23 for setting the search area SA or SA′ as shown in FIG. 4a and FIG.4b.

This table T gives the relationship between the number of the macroblock MBN to be predicted that is specified in the current frame imageGN and the number of macro block MB in the previous image GR that is tobe included in the search area SA or SA′ that is set in the previousframe image GR. Here, the regular width of the search area SA is thewidth that includes a total of 25 macro blocks MB in 5 rows and 5columns with the macro block MBR in the previous frame image as thecenter. The macro block MBR corresponds to the macro block MBN to bepredicted.

Also, as shown in FIG. 5B, when the number of the macro block MBN to bepredicted is “106”, the search area SA becomes the search area SA shownin FIG. 5B. However, when the number of the macro block MBN to bepredicted is “156”, the search area SA′ becomes the search area SA′shown in FIG. 5B. Here, since the macro block MBN to be predicted, whosenumber is “156”, is near the boundary line L, the width of the searcharea SA′ becomes narrower than the width of the search area SA.

When the control circuit 22 is instructed via the CPU 12 tosimultaneously record the input data Sina and Sinb, the control circuit22 reads the table T from the table memory 23 as a table signal Stm andsets the macro block MEN to be predicted based on the number of themacro block MB in the current frame image GN that is input as numberdata Sma. The control circuit 22 also sets the corresponding search areaSA or SA′ in the previous frame image GR and outputs a control signalSmc to the motion-prediction-compensation circuit 36 in order to detectmotion.

The motion-prediction-compensation circuit 36 detects the motion vectorsbetween the image GRA and image GRE, as shown in FIG. 4A and FIG. 4A,and executes the motion-prediction-compensation process using the motionvectors for all of the frame images that are input as macro blocksignals Smb. The motion-prediction-compensation circuit 36 also createsa compensation signal Se and outputs that signal to the subtracter 30and adder 37.

In addition to the table T mentioned above., there is also a tablestored in the table memory 23 that is used when compressing, coding andrecording input data Sina from only one source. In this table, thesearch area is set as was done in the prior technology irrespective ofthe boundary line L in the table T. When the control circuit 22compresses and codes input data Sina from only one source, it sets thesearch area using this table and outputs a control signal Smc to detectthe motion vector and to execute the motion-prediction-compensationprocess.

Next, the variable-length coding circuit 25 to which the quantizationsignal Sq is input, performs variable-length coding of the quantizationsignal Sq in macro block MB units, and creates compressed image dataSpd, which is a signal of the frame images that are contained in theoriginal composite image data Scv and which is compressed and codedseparately for the images that correspond to the input data Sina andimages that correspond to the input data Sinb, and then outputs the datain the order of the number of macro block MB to the control circuit 22and header-generator 26.

Then, according to a control signal Sh from the control circuit 22, theheader generator 26 independently stores the picture element datacontained in each of the macro blocks MB in the compressed image dataSpd, which was input in order of the number of the macro block MB, forthe picture element data that corresponds to the input data Sina and thepicture element data that corresponds to the input data Sinb, andsimilarly independently adds various types of headers in MPEG format tothe data.

At this time, according to the number of the macro block MB input asnumber data Sma, the control circuit 22 specifies for each macro blockMB in the compressed image data Spd whether it is a macro block thatcontains the picture element data corresponding to the input data Sina,or whether it is a macro block that contains the picture element datacorresponding to the input data Sinb, and generates a control signal Shto store that specified picture element data independently in the headermemory.

In more detail, as shown in FIG. 6, the picture element data that arecontained in each of the macro blocks MB that are input as compressedimage data Spd, are stored in the header memory 26 a in the headergenerator 26, in the order that the data were input, and the variousheader necessary to configure a MPEG format data stream are stored intheir corresponding areas.

As shown in FIG. 6, the types of headers are: sequence headers SCH,which are added to the start of a sequence; Group of Picture (GOP)headers GH, which are added to the start of a group of pictures; pictureheaders PH, which are added to the start of pictures in a frame image(in conventional MPEG format, this includes 1,320 macro blocks MB);slice headers SH, which are added to the start of each slice SL; andsequence end code SEC, which is added to the end of a sequence.

At this time, as shown in FIG. 6, image data DA that correspond to theinput data Sina and image data DB that correspond to the input data Sinbare stored in separate areas of the header memory 26 a in the order theywere input, and furthermore, a header is added separately for each ofthe image data DA or image data DB. Also, in the header memory 26 a, onepicture comprises the picture element data corresponding to 660 macroblocks MB, and one slice SL comprises the picture element datacorresponding 22 macro blocks MB.

Next, each of the picture element data stored in the header memory 26 ais read from the header memory 26 a as stream data Sst alternately forthe image data DA and the image data DB, and then output to the switch27.

Here, as shown in FIG. 7, the stream data Sst comprises a sequence (theportion of data from the sequence header SCH to the sequence end codeSEC) of the image data DA and similarly a sequence of the image data DBthat are separately and alternately linked in a continuous stream.

Furthermore, when the header generator 26 outputs the stream data Sst,it creates switch-timing data Scgg, which indicates the timing forswitching between the image data DA and the image data DB in the streamdata Sst, and outputs it to the control circuit 22.

Next, according to a control signal Scw4 that is output from the controlcircuit 22 based on the switch-timing data Scgg, the switch 27 switchesso as to output the portion in the stream data Sst that corresponds tothe image data DA to the output buffer 28 a as stream data Ssta, andoutput the portion in the stream data Sst that corresponds to the imagedata DB to the output buffer 28 b as stream data Sstb. At this time, theswitch 27 switches to the output buffer 28 a when the portion in thestream data Ssst that corresponds to the image data DA is input, andswitches to the output buffer 28 b when the portion in the stream datathat corresponds to the image data DB is input.

The output buffers 28 a and 28 b temporarily and independently storesthe stream data Ssta and Sstb, then create a storage-amount signal Sddthat indicates the amount stored in each output buffer and output thatsignal to the control circuit 22.

From the storage-amount signal Sdd, the control circuit 22 is aware ofthe amount stored in the output buffers, and creates the aforementionedrate signal Srr in order to control the processing rate for thequantization circuit 32.

Next, based on the processing rate in the switch-timing data Scgg andquantization circuit 32, the control circuit 22 creates a control signalScw5 for controlling the timing for outputting the stream data Ssta orSstb from the output buffers, and outputs that signal to the switch 29.

From this, the stream data Ssta and Sstb are output separately to themultiplexing circuit 11 as coded image data Sed with the timing given bythe control signal Scw5.

At the same time as this, the control circuit 22 creates the timingsignal St for synchronizing the timing between coded sound data Seaa orSeab and the coded image data Sed in the multiplexing circuit 11, andoutputs that signal to the multiplexing circuit 11.

In the case where input data from only one source is coded in the imagecoding circuit 10, timing control is performed using only one of theoutput buffers 28 a or 28 b in the buffer unit 28.

Next, FIG. 8 is used to explain the construction and operation of themultiplexing circuit 11.

First, as shown in FIG. 8, the multiplexing circuit 11 is comprised ofan image buffer 40, a first sound buffer 41, a second sound buffer 42, aswitch 43 and a multiplexer 44.

Next, the operation will be explained.

First, the image buffer 40 temporarily stores the coded image data Sedthat is output from the image-coding circuit 10, and outputs the data tothe multiplexer 44 with the timing given by the timing signal St.

At the same time, the first sound buffer 41 temporarily stores the codedsound data Seaa that is output from the sound-coding circuit 6, andoutputs the data to one of the input terminals of the switch 43.

The second sound buffer 42 temporarily stores the coded sound data Seabthat is output from the sound-coding circuit 7, and outputs the data tothe other input terminal of the switch 43.

Then, based on the timing signal St, the switch 43 reads the coded sounddata Seaa from the first sound buffer 41 at the timing that the imagedata DA shown in FIG. 7 is output to the multiplexer 44, and outputsthat data to the multiplexer 44, and also reads the coded sound dataSeab from the second sound buffer 42 at the timing that the image dataDB shown in FIG. 7 is output to the multiplexer 44, and outputs thatdata to the multiplexer 44.

The multiplexer 44 performs multiplexing on the coded sound data Seaa,which contains sound data that corresponds to the image data DA, andcreates multiplex data Smx and outputs it to the recording unit 13, andalso performs multiplexing on the coded sound data Seab, which containssound data that corresponds to the image data DB, and creates multiplexdata Smx and outputs it to the recording unit 13.

Then, in the recording unit 13, the recording process described above isexecuted for each respective multiplex data Smx and recording data Sr iscreated.

At this time, the data that corresponds to the original input data Sinaand the data that corresponds to the original input data Sinb arecontained separately and independently in the recording data Sr (forexample in separate file format), and these data are also recorded onthe recording medium 14 in a form such that they can be handledseparately and independently.

As explained above, with the image-coding circuit 10 of the datarecording apparatus of this embodiment, the respective frame images ofthe image data Sva and Svb are collected as composite image data Scv,and the coding process is executed separately for each, so it ispossible to code a plurality of moving images simultaneously with asingle image-coding circuit 10.

Moreover, in the motion-prediction-compensation process, the search areaSA or SA′ is set and the motion vectors are detected only within therange of the images GVMA or GVMB (see FIG. 4A and FIG. 4B) so it ispossible to code a plurality of moving images with the saint codingmethod as used for non-composite moving images.

Moreover, in the motion-prediction-correction process, the search areaSA or SA′ is set and the motion vectors are detected only within therange of the images GVMA or GVMB (see FIG. 4A and FIG. 4B) so it ispossible to code a plurality of moving images with the same codingmethod as used for non-composite moving images.

Furthermore, each process is executed based on the MPEG format so it ispossible to compress and code a plurality of moving imagessimultaneously.

Also, sound data Saa or Sab is coded at the same time as coding of themoving images, and then combined, so it is possible to code and recordinput data Sina and Sinb from two sources simultaneously.

An embodiment in which the present invention is applied to a datarecording apparatus R, which uses a coding format that complies with theMPEG format, was described above, however, the present invention mayalso be applied to any coding method that sets up a search area anddetects the motion vectors.

Furthermore, it is also possible to apply the present invention tocreate composite image data from input data from three or more sources,and not just coding of input data from two sources.

In this case, the arrangement of image data that corresponds to all ofthe input data in the composite image data may be arranged in thevertical direction and not just the horizontal direction as in the caseof the embodiment described above.

Furthermore, by recording a program that corresponds to the operation ofthe image-coding circuit 10, which includes the control circuit 22, on arecording medium such as a flexible disc or hard disc, it is possiblefor a personal computer or the CPU of a normal coding apparatus to readand execute the program and function as the image-coding circuit 10 ofthis embodiment.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the forgoing descriptionand all changes which come within the meaning and range of equivalencyof the claims are therefore intended to be embraces therein.

The entire disclosure of Japanese Patent Application No. 2000-217979filed on Jul. 18, 2000 including the specification, claims, drawings andsummary is incorporated herein by reference in its entirety.

What is claimed is:
 1. An image coding apparatus, which codes movingimages by coding a composite frame image that is obtained by forming aboundary between frame images, each forming a plurality of differentmoving images, and by connecting the frame images, comprising: amotion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; and a control device for controlling saidmotion-prediction-compensation device, quantization device and codingdevice such that said motion prediction compensation, quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively.
 2. The image-coding apparatusaccording to claim 1, wherein said motion-prediction-compensation deviceexecutes said motion prediction compensation by detecting a motionvector, and detects the motion vector by setting a search area for saidmotion prediction compensation within only a range of said frame imagescontained in said composite frame image, and detecting the motionvector.
 3. The image-coding apparatus according to claim 1, wherein saidquantization device independently performs said quantization for each ofsaid frame image in said composite frame image.
 4. The image-codingapparatus according to claim 1, further comprising a discrete cosinetransform device for performing discrete cosine transform of each saidframe image based on the results of said motion prediction compensationthat is performed on each said frame image, wherein said quantizationdevice performs said quantization for each of said frame image of whichdiscrete cosine transform is performed.
 5. The image-coding apparatusaccording to claim 1, wherein said motion prediction compensation,quantization process and coding process are executed according to MovingPicture Experts Group (MPEG) format.
 6. A data-coding apparatus, whichincludes an image-coding apparatus for coding moving images by coding acomposite frame image that is obtained by foaming a boundary betweenframe images, each forming a plurality of different moving images, andby connecting the frame images, said image-coding apparatus comprising:a motion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; and a control device for controlling saidmotion-prediction-compensation device, quantization device and codingdevice such that said motion prediction compensation, quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively, said data-coding apparatuscomprising: a separation device for separating moving images and sounddata from a plurality of input data that contain said moving images andsaid sound data that correspond to said moving images; a firstcomposite-image device for reducing an amount of data in said frameimages of said separated moving images by thinning out the data, and forgenerating said composite frame image to output that image to saidimage-coding apparatus; a sound-coding device for coding said separatedsound data simultaneously with coding of the corresponding said movingimages and for generating coded sound data; and a second composite-imagedevice for combining corresponding said coded moving images and saidcoded sound data and for generating a plurality of said coded inputdata.
 7. A data-recording apparatus, which includes an image-codingapparatus for coding moving images by coding a composite frame imagethat is obtained by forming a boundary between frame images each forminga plurality of different moving images, and by connecting the frameimages, said data-recording apparatus comprising: amotion-prediction-compensation device for independently performingmotion prediction compensation for each of said frame images in saidcomposite frame image; a quantization device for performing quantizationfor each of said frame images based on the results of said motionprediction compensation that is performed for each said frame image; acoding device for coding said moving images by coding each said frameimage based on the results of said quantization that is performed foreach said frame image; a control device for controlling saidmotion-prediction-compensation device, quantization device and codingdevice such that said motion prediction compensation quantization andcoding are performed for a plurality of continuous composite-frameimages by said motion-prediction-compensation device, quantizationdevice and coding device, respectively; a separation device forseparating moving images and sound data from a plurality of input datathat contain said moving images and said sound data that correspond tosaid moving images; a first composite-image device for reducing anamount of data in said frame images of said separated moving images bythinning out the data, and for generating said composite frame image tooutput that image to said image-coding apparatus; a sound-coding devicefor coding said separated sound data simultaneously with coding of thecorresponding said moving images and for generating coded sound data; asecond composite-image device for combining corresponding said codedmoving images and said coded sound data and for generating a pluralityof said coded input data; and a recording device for separatelyrecording said coded input data on a recording medium.
 8. Animage-coding method for coding moving images by coding a composite frameimage tat is obtained by forming a boundary between frame images, eachforming a plurality of different moving images, and by connecting theframe images, comprising the processes of: independently performingmotion prediction compensation for said frame images in said compositeframe image; performing quantization for each of said frame images basedon the results of said motion-prediction-compensation that is performedfor each of said frame images; coding said moving images by coding eachof said frame images based on the results of said quantization that isperformed for each of said frame images; and repeating said motionprediction compensation, quantization and coding for a plurality ofcontinuous said composite frame images.
 9. The image-coding methodaccording to claim 8, wherein said process of independently performingmotion prediction compensation executes saidmotion-prediction-compensation by setting a search area for saidmotion-prediction-compensation within only the range of said frameimages that are included in one said composite frame image and detectingthe motion vectors.
 10. The image-coding method according to claim 8,wherein said process of performing quantization independently performsquantization for each of said frame images in said composite frameimage.
 11. The image-coding method according to claim 8, furthercomprising the process of performing discrete cosine transform for eachof said frame images based on the results of saidmovement-prediction-compensation that is performed for each of saidframe images, and wherein said process for performing quantizationexecutes quantization for each of said frame images after discretecosine transformation.
 12. The image-coding method according to claim 8,wherein said motion prediction compensation, quantization and coding areexecuted based on MPEG format.
 13. A data-coding method that includesthe image-coding method for coding said moving images by coding acomposite frame image that is obtained by forming a boundary betweenframe images, each forming a plurality of different moving images, andby connecting the frame images said image-coding method comprising theprocesses of: independently performing motion prediction compensationfor said frame images in said composite frame image; performingquantization for each of said frame images based on the results of saidmotion-prediction-compensation that is performed for each of said frameimages; and coding said moving images by coding each of said frameimages based on the results of said quantization that is performed foreach of said frame images; and repeating said motion predictioncompensation, quantization and coding for a plurality of continuous saidcomposite frame images, said data-coding method comprising the processesof: separating moving images and sound data from a plurality of inputdata that includes said moving images and corresponding sound data;generating said composite-frame image to execute said image-codingmethod after reducing the amount of data in said frame images containingsaid separated moving images; coding each of separated said sound datasimultaneously with coding of corresponding said moving images togenerate coded sound data; and combining corresponding said coded movingimages and said coded sound data to generate a plurality of said codedinput data.
 14. A data-recording medium on which an image-coding programis recorded so that it is readable by a computer, which is included inan image-coding apparatus that codes said moving images by coding acomposite-frame image that is obtained by forming a boundary betweenframe images, each forming a plurality of different moving images, andby connecting the frame images, said image-coding program causing thecomputer to function as: a motion-prediction-compensation device forindependently performing a motion prediction compensation for each ofsaid frame images in said composite frame image; a quantization devicefor performing quantization for each of said frame images based on theresults of said motion prediction compensation that was performed foreach said frame image; a coding device for coding said moving images bycoding each said frame image based on the results of said quantizationthat was performed for each said frame image; and a control device forcontrolling said motion-prediction-compensation device, quantizationdevice and coding device such that said motion prediction compensation,quantization and coding are preformed for a plurality of continuouscomposite-frame images by said motion-prediction-compensation device,quantization device and coding device, respectively.
 15. Thedata-recording medium according to claim 14, wherein saidmotion-prediction-compensation device performs said motion predictioncompensation by setting the search area for themotion-prediction-compensation within only the range of said frameimages that are included in one said composite-frame image and detectingthe motion vectors.
 16. The data-recording medium according to claim 14,wherein said quantization device performs quantization independently foreach of said frame images in said composite-frame image.
 17. Thedata-recording medium according to claim 14, said image-coding programfurther causing the computer to function as: a discrete cosine transformdevice for performing discrete cosine transformation of each of saidframe images based on the results of said motion-prediction-compensationthat is performed for each of said frame images, wherein saidquantization device performs quantization for each of said frame imagesafter discrete cosine transformation.
 18. The data-recording mediumaccording to claim 14, wherein said motion-prediction-compensation,quantization and coding are executed based on MPEG format.
 19. Adata-recording medium on which a coding program is recorded so that itis readable by a computer, which is included in a data-coding apparatusthat includes an image-coding apparatus that codes said moving images bycoding a composite-frame image that is obtained by forming a boundarybetween frame images each forming a plurality of different movingimages, and by connecting the frame images, said coding program thatincludes an image-coding program causing the computer to function assaid image-coding apparatus comprising a motion-prediction-compensationdevice for independently performing a motion prediction compensation foreach of said frame images in said composite frame image; a quantizationdevice for performing quantization for each of said frame images basedon the results of said motion prediction compensation that was performedfor each said frame image; a coding device for coding said moving imagesby coding each said frame image based on the results of saidquantization that was performed for each said frame image; and a controldevice for controlling said motion-prediction-compensation device,quantization device and coding device such that said motion predictioncompensation, quantization and coding are performed for a plurality ofcontinuous composite-frame images by said motion-prediction-compensationdevice, quantization device and coding device, respectively, whereinsaid coding program further causing the computer to function as: aseparation device for separating moving images and sound data from aplurality of input data that includes said moving images andcorresponding sound data; a first composite-image device for reducingthe amount of data in said frame images containing said separated movingimages, and for generating said composite-frame image to output tatimage to said computer functioning as said image-coding apparatus; asound-coding device for coding each of separated said sound datasimultaneously with coding of corresponding said moving images, and forgenerating coded sound data; and a second composite-image device forcombining corresponding said coded moving images and said coded sounddata, and for generating a plurality of said coded input data.